#include "ex13_34.cpp"
#include <set>
#include <string>

using namespace std;
class Folder {
public:
  Folder();
  ~Folder();
  Folder &operator=(const Folder &);
  Folder(const Folder &);

  void addMsg(Message *m3) { messages.insert(m3); }
  void remMsg(Message *ms) { messages.erase(ms); }

private:
  set<Message *> messages;
};
